Numerous fungi and bacteria are serious pests of common agricultural crops. One method of controlling diseases has been to apply antimicrobial organic or semiorganic chemicals to crops or seeds. This method has numerous, art-recognized problems. A more recent method of controlling pathogenic microorganisms has been the use of biological control organisms which are typically natural competitors or inhibitors of the troublesome microorganisms. However, it is difficult to apply biological control organisms to large areas, and even more difficult to assure that those living organisms will persist in the treated area for an extended period. Still more recently, techniques in recombinant DNA have provided the opportunity to insert into plant cells cloned genes which express peptides of interest, some of which are antimicrobial. This technology has given rise to additional concerns about eventual microbial resistance to well-known, naturally occurring antimicrobials, particularly in the face of heavy selection pressure, which may occur in some areas. Thus, a continuing need exists to identify naturally occurring antimicrobial compounds which can be formed by plant cells, either directly or indirectly, by translation of a single structural gene.
European Patent Application 204,590, based upon U.S. patent application Ser. No. 725,368, describes a method of genetically modifying a plant cell to control expression of heterologous foreign structure genes. In the method, the plant cell is transformed to contain a pRi T-DNA promoter and a heterologous foreign structural gene, the promoter and the structural gene being in such position and orientation with respect to one another that the structural gene is expressible in a plant cell under control of the promoter.
Likewise, European Patent Application 186,425, based upon U.S. patent application Ser. No. 685,824, describes a recombinant DNA expression vector which comprises (a) a transcription unit, flanked by T-DNA border sequences, which comprises a promoter and associated amino terminal region encoding sequences and a terminator signal sequence in which the sequences are derived from one or more genes which are naturally expressed in a plant cell, and (b) an antibiotic resistance gene-encoding sequence located between the promoter and associated amino-terminal region-encoding sequence and the terminator sequence and (c) a DNA fragment containing a replicon that is functional in Agrobacterium.
PCT application 8807087, based upon U.S. patent application Ser. No. 168,109, discloses a recombinant virus expression system comprising a Heliothis polyhedrin promoter and a nucleotide sequence encoding a heterologous peptide or protein, which may have antimicrobial activity.
Akaji, K. et al., Chem. Pharm. Bull. (Tokyo) 37(10):2661-2664 (1989), reports is the syntheses of three peptides from horseshoe crab, including tachyplesin I and II.
Kawano, K. et al., J. Biol. Chem. 265(26):15365-15367 (1990), reports the isolation of tachyplesin I from hemocytes of the horseshow crab, and determination of its beta-sheet structure.
Miyata, T. et al., J. Biochem (Tokyo) 106(4):663-669 (1989), discloses isolation of tachyplesin II from horseshoe crab and elucidation of its structure and biological activity.
Muta, T. et al., J. Biochem (Tokyo) 108(2):261-266 (1990), discloses isolation of tachyplesin III and a processing intermedate of its precursor.
Nakamura, T. et al., J. Biol. Chem. 263(32):16709-16713 (1988), discusses isolation and chemical structure of tachyplesin.
Niwa, M. et al., First Scientific Meeting of the Japanese Association for Developmental and Comparative Immunology (Jadci), Tokyo, Japan, November (14(2):2-3 (1990) deals with the antimicrobial activities of tachyplesin isopeptides.
Shieh, T. C. et al., FEBS (Fed. Eur. Biochem. Soc.) Lett. 252(1-2):121-124 (1989) discloses synthesis and properties of tachyplesin I.
Shigenaga, T. et al., J. Biol. Chem.. 265(34):21350-21354 (1990) describes cloning of cDNA for the peptide precursor of tachyplesin and the cellular localization of the peptide in the horseshoe crab.
Japanese laid-open patent application 02207098, assigned to Taiyo Fishery KK, disloses a composition having high specificity to beta-glucan. The composition includes an amoebocyte lysate from Lumulina and blood cell membrane proteins including tachyplesins I and II.
Japanese laid-open patent application 02204500, also assigned to Taiyo Fishery KK, discloses an article insoluble carrier for removing pyrogens from fluids. The article is made by bonding crab peptides identified as tachyplesins I and II to a water-insoluble carrier.
Prior copending, commonly assigned application Ser. No. 07/802,794, filed Dec. 6, 1991, "Peptide with Inhibitory Activity Towards Plant Pathogenic Fungi", the European counterpart of which was published Jun. 6, 1993, relates to the discovery that tachyplesins also have activity against fungal pathogens of common crop plants.
The disclosures of the foregoing references are hereby incorporated herein in their entirety by reference to show the state of the art.